title: GLABROUS INFLORESCENCE STEMS regulates trichome branching by genetically interacting with SIM in Arabidopsis.
abstract: Arabidopsis trichomes are large branched single cells that protrude from the epidermis. The first morphological indication of trichome development is an increase in nuclear content resulting from an initial cycle of endoreduplication. Our previous study has shown that the C2H2 zinc finger protein GLABROUS INFLORESCENCE STEMS (GIS) is required for trichome initiation in the inflorescence organ and for trichome branching in response to gibberellic acid signaling, although GIS gene does not play a direct role in regulating trichome cell division. Here, we describe a novel role of GIS, controlling trichome cell division indirectly by interacting genetically with a key endoreduplication regulator SIAMESE (SIM). Our molecular and genetic studies have shown that GIS might indireclty control cell division and trichome branching by acting downstream of SIM. A loss of function mutation of SIM signficantly reduced the expression of GIS. Futhermore, the overexpression of GIS rescued the trichome cluster cell phenotypes of sim mutant. The gain or loss of function of GIS had no significant effect on the expression of SIM. These results suggest that GIS may play an indirect role in regulating trichome cell division by genetically interacting with SIM.
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Sun
authors.forename: Zhong-Jing
authors.initials: ZJ
authors.lastname: Zhou
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: An
authors.forename: Yan
authors.initials: Y
authors.lastname: An
authors.forename: Yong-Qin
authors.initials: YQ
authors.lastname: Zhao
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Meng
authors.forename: Clare
authors.initials: C
authors.lastname: Steele-King
authors.forename: Yin-Bo
authors.initials: YB
authors.lastname: Gan
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002455:Cell Division; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D005875:Gibberellins / Q000378:metabolism; D056626:Inflorescence / Q000235:genetics; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D010641:Phenotype; D018749:RNA, Plant / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D064201:Trichomes / Q000254:growth & development*; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; C512212:GIS protein, Arabidopsis; D005875:Gibberellins; D018749:RNA, Plant; C517317:SIAMESE protein, Arabidopsis; D014157:Transcription Factors; C007842:gibberellic acid